This packet covers the rules for zero and negative exponents. We have videos for you to learn from, and several examples.
Source: Greene
This video shows you how to deal with negative and zero exponents.
This is another video showing a slightly different way of thinking about zero exponents.
This page has some great examples on negative and zero exponents, as well as explaining the rationale behind it very well.
http://www.homeschoolmath.net/teaching/negative_zero_exponents.php
